Pulmonary fibroproliferation is a steroptypical reparative reaction to tissue (epithelial cells and the striking accumulation of mesenchymal cells and their connective tissue products in the airspaces and walls of the intraacinar micro-vessels. Mortality in late ARDS is related directly or indirectly to pulmonary fibroproliferation. The goal of this prospective doubleblind, randomized clinical trial is to evaluate the effects of cortiscosteroid therapy on lung injury and outcome in patients with late ARDS.